Edible water-soluble film

ABSTRACT

Disclosed herein are water-soluble films and resulting packets including a water soluble film, wherein the water-soluble film includes a water-soluble mixture of polyvinyl alcohol, a compatibilizing agent, and a sugar alcohol plasticizer that is a solid at room temperature, wherein the water-soluble film is substantially transparent.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to water-soluble films. Moreparticularly, the disclosure relates to edible water-soluble filmscomprising a mixture of a first water-soluble polymer, a compatibilizerpolymer, and a sugar alcohol plasticizer that is a solid at roomtemperature.

BACKGROUND

Water-soluble films are well known in the art. Water-soluble films havemany applications, including non-edible forms, such as packagingmaterials, and edible forms, wherein the film itself is or makes up anedible article. Edible films are known for uses such as delivery oftherapeutic agents, breath freshening agents, and flavors.

When a food ingredient is provided in a traditional packaged state, thepackage must be torn or otherwise opened to remove the contents prior tocooking or eating. This is not only troublesome, but also has thedisadvantage that the contents can tend to be spilled at the time ofopening the packages, especially when they are in powder or liquid form.One solution is to package such contents with an edible film. If thepackaging material is soluble in water, the package can be dissolvedsimply by pouring water over it or immersing it in the water, thusmaking it unnecessary to tear the package. Accordingly, it is highlydesirable to package food contents with such a film.

Various edible water-soluble films known in the art have one or moredeficiencies, including that they are not easily converted into packetsor pouches, or they are particularly tough, or they are cold watersoluble only. Therefore, these films cannot be used in applications thatwould require hot water to be added directly to the package, such aspackaging for oatmeal, cocoa, or soup mixes. Additionally, it is knownin the art that water-soluble films that contain a high level of sugaralcohols are often not transparent due to crystallization of or bleedingout of the sugar alcohol. In food packaging applications, it would beadvantageous to package food contents in a water-soluble film that coulddissolve in either hot or cold water and maintain transparency.

SUMMARY

One aspect of the disclosure is a water-soluble film including awater-soluble mixture of polyvinyl alcohol, a compatibilizing agent, anda sugar alcohol plasticizer that is a solid at room temperature, whereinthe water-soluble film is substantially transparent.

Another aspect of the disclosure is a water-soluble film including awater-soluble mixture of polyvinyl alcohol, a compatibilizing agent,xylitol and a second sugar alcohol plasticizer that is a solid at roomtemperature, wherein the water-soluble film at about 2.0 mils thickcompletely dissolves in less than 50 seconds, preferably less than 40and most preferably less than 30 at 23° C., optionally wherein thecompatibilizing agent is carboxymethyl cellulose.

Still another aspect of the disclosure is a water-soluble film includinga water-soluble mixture of polyvinyl alcohol, a compatibilizing agent,xylitol and a second sugar alcohol plasticizer that is a solid at roomtemperature, wherein the water-soluble film at about 2.0 mils thickcompletely dissolves in less than 50 seconds, preferably less than 40and most preferably less than 30 at 23° C., and wherein thewater-soluble film has a tear strength of at least 400 g/mil, optionallywherein the compatibilizing agent is carboxymethyl cellulose.

Still another aspect of the disclosure is a water-soluble film includinga water-soluble mixture of polyvinyl alcohol, a compatibilizing agent,and a sugar alcohol plasticizer that is a solid at room temperature,wherein the sugar alcohol plasticizer that is a solid at roomtemperature is included in the mixture in an amount of about 20 phr orless, and is characterized by a heat of fusion of about 247 J/g or less.

Still another aspect of the disclosure is a water-soluble film includinga water-soluble mixture of polyvinyl alcohol, a compatibilizing agent,and a sugar alcohol plasticizer that is a solid at room temperature,wherein the sugar alcohol plasticizer that is a solid at roomtemperature is included in the mixture in an amount of about 30 phr, forexample about 29 phr to about 31 phr or about 25 phr to about 35 phr.

Optionally, the water-soluble films of each aspect can be thermoformedinto a pouch.

Further aspects and advantages will be apparent to those of ordinaryskill in the art from a review of the following detailed description.While the compositions and methods are susceptible of embodiments invarious forms, the description hereafter includes specific embodimentswith the understanding that the disclosure is illustrative, and is notintended to limit the invention to the specific embodiments describedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a top view of a Mylar template for determining the percentopacity of water-soluble films illustrating the designation of the fivesampling areas, according to the Examples below.

FIG. 1b is a top view of the Mylar template of FIG. 1a for determiningthe percent opacity of water-soluble films, illustrating the placementof the five sampling areas on the Mylar template.

FIG. 2 is a plot of the tear strength of water-soluble films vs. theweight percent of xylitol included in the water-soluble films accordingto Example 1.

FIG. 3 is a plot of the dissolution time of water-soluble films vs. theweight percent of xylitol included in the water-soluble films accordingto Example 1.

FIG. 4 is a contour plot of the tear strengths of PVOH basedwater-soluble films with different loadings of CMC and xylitol accordingto Example 1.

DETAILED DESCRIPTION

Disclosed herein are water-soluble films comprising a water-solublemixture of a first water-soluble polymer, a polymer compatibilizer (forexample a cellulose ether polymer or a modified starch), and a sugaralcohol plasticizer that is a solid at room temperature. Optionally, thewater-soluble films are edible. The water-soluble films of one aspect ofthe disclosure can be particularly advantageous in that they can bedesigned such that the transparency of the water-soluble film ismaintained for long periods of time. The water-soluble films of thedisclosure herein can have one or more other, optional advantagesincluding thermoformability (e.g., into packets) and suitable toughnessfor use as packaging materials. For example, optional edible embodimentscan be designed according to the disclosure herein to have suitablerobustness, e.g. for use as packaging. In particular, water-solublefilms according to one class of embodiments of the disclosure candemonstrate unexpectedly advantageous tear strength and furtheroptionally an unexpectedly advantageous solubility.

As used herein, the term “comprising” indicates the potential inclusionof other agents, elements, steps, or features, in addition to thosespecified.

As used herein and unless specified otherwise all measurements of PVOHviscosity in centipoise (cP) are of a 4% solution at 20° C., and allmeasurements of carboxymethyl cellulose viscosity are of a 2% solutionat 25° C.

As used herein, “substantial transparency” refers to a water-solublefilm that, when cast to a thickness of about 2.0 mm, has a measuredopacity of about 37.0% or less, as determined by an X-RITE SP60 SeriesSphere Spectrophotometer X-64 colorimeter as described herein, orsubstantial equivalent, after storing for at least 30 days.

As used herein, “Δ% opacity” refers to the change in opacity, asdetermined by an X-RITE SP60 Series Sphere Spectrophotometer X-64colorimeter as described herein, or substantial equivalent, between theopacity of a film at t=0 after film forming, and the opacity of the samefilm after conditioning and storage.

As used herein, “enhanced transparency” refers to a water-soluble filmaccording to the disclosure herein that, when cast to a thickness ofabout 2.0 mils, demonstrates an opacity of 37.0% or less, as determinedby an X-RITE SP60 Series Sphere Spectrophotometer X-64 colorimeter asdescribed herein, or substantially equivalent, optionally after storingfor at least 30 days.

As used herein, “favorable solubility” refers to a film according to thedisclosure herein that, at about 2.0 mils thick, completely dissolves inless than 50 seconds, preferably less than 40 and most preferably lessthan 30 seconds in water at 23° C.

As used herein, “good tear strength” refers to a tear strength of atleast 400 g/mil at 23° C. as measured by an Elmdorf Tearing Tester modelnumber 40043, or equivalent.

As used herein and unless specified otherwise, the terms “wt. %” and “wt%” are intended to refer to the composition of the identified element in“dry” (non water) parts by weight of the entire film (when applicable)or parts by weight of the entire composition enclosed within a pouch(when applicable). As used herein and unless specified otherwise, theterm “phr” is intended to refer to the composition of the identifiedelement in parts per one hundred parts water-soluble PVOH resins.

Water-soluble films, optional ingredients for use therein, and methodsof making the same are well known in the art. In one class ofembodiments, the water-soluble film includes polyvinyl alcohol (PVOH).PVOH is a synthetic resin generally prepared by the alcoholysis, usuallytermed hydrolysis or saponification, of polyvinyl acetate. Fullyhydrolyzed PVOH, wherein virtually all the acetate groups have beenconverted to alcohol groups, is a strongly hydrogen-bonded, highlycrystalline polymer which dissolves only in hot water—greater than about140° F. (60° C.). If a sufficient number of acetate groups are allowedto remain after the hydrolysis of polyvinyl acetate, the PVOH polymerthen being known as partially hydrolyzed, it is more weaklyhydrogen-bonded and less crystalline and is soluble in cold water—lessthan about 50 ° F. (10° C.). An intermediate cold/hot water soluble filmcan include, for example, intermediate partially-hydrolyzed PVOH (e.g.,with degrees of hydrolysis of about 94% to about 98%), and is readilysoluble only in warm water—e.g., rapid dissolution at temperatures ofabout 40° C. and greater. Both fully and partially hydrolyzed PVOH typesare commonly referred to as PVOH homopolymers although the partiallyhydrolyzed type is technically a vinyl alcohol-vinyl acetate copolymer.

The degree of hydrolysis (DH) of the PVOH included in the water-solublefilms of the present disclosure can be about 75% to about 99%. As thedegree of hydrolysis is reduced, a film made from the resin will havereduced mechanical strength but faster solubility at temperatures belowabout 20° C. As the degree of hydrolysis increases, a film made from theresin will tend to be mechanically stronger and the thermoformabilitywill tend to decrease. The degree of hydrolysis of the PVOH can bechosen such that the water-solubility of the resin is temperaturedependent, and thus the solubility of a film made from the resin,compatibilizer polymer, and additional ingredients is also influenced.In one class of embodiments the film is cold water-soluble. A coldwater-soluble film, soluble in water at a temperature of less than 10 °C., can include PVOH with a degree of hydrolysis in a range of about 75%to about 90%, or in a range of about 80% to about 90%, or in a range ofabout 85% to about 90%. In another class of embodiments the film is hotwater-soluble. For example, a hot water-soluble film is advantageous foredible applications such as water-soluble packets enclosing a hot fooditem, e.g. oatmeal, cocoa, or soup mix. A hot water-soluble film,soluble in water at a temperature of at least about 60° C., can includePVOH with a degree of hydrolysis of at least about 98%.

Other film-forming, water soluble resins for use in addition to or in analternative to PVOH can include, but are not limited to modifiedpolyvinyl alcohols, polyacrylates, water-soluble acrylate copolymers,polyvinyl pyrrolidone, pullulan, water-soluble natural polymersincluding, but not limited to, guar gum, xanthan gum, carrageenan, andstarch, water-soluble polymer derivatives including, but not limited to,ethoxylated starch and hydroxypropylated starch, copolymers of theforgoing and combinations of any of the foregoing.

The water-soluble polymers can be included in the film composition in anamount in a range of about 30 wt. % to about 90 wt. %, for example. Theweight ratio of the amount of the water-soluble polymer as compared tothe combined amount of all plasticizers, compatibilizing agents, andsecondary additives can be in a range of about 0.5 to about 9, about 0.5to about 5, or about 1 to 3, or about 1 to 2, for example.

Water-soluble polymers for use in the films described herein (including,but not limited to PVOH polymers) can be characterized by a viscosity ina range of about 3.0 to about 27.0 cP, or about 3.0 cP to about 15 cP,or about 6.0 to about 10.0 cP. The viscosity of a PVOH polymer isdetermined by measuring a freshly made solution using a Brookfield LVtype viscometer with UL adapter as described in British Standard EN ISO15023-2:2006 Annex E Brookfield Test method. It is internationalpractice to state the viscosity of 4% aqueous polyvinyl alcoholsolutions at 20 ° C. All viscosities specified herein in cP should beunderstood to refer to the viscosity of 4% aqueous polyvinyl alcoholsolution at 20° C., unless specified otherwise.

It is well known in the art that the viscosity of a PVOH polymer iscorrelated with the weight average molecular weight (Mw) of the samePVOH polymer, and often the viscosity is used as a proxy for Mw. Thus,the weight average molecular weight of the water-soluble polymer can bein a range of about 30,000 to about 175,000, or about 30,000 to about100,000, or about 55,000 to about 80,000.

In one class of embodiments, the molecular weight of the water-solublepolymer is in the range of about 55,000 to about 80,000. Unexpectedly, awater-soluble film according to the disclosure comprising polymers withmolecular weights in the range of about 55,000 to about 80,000,demonstrate enhanced transparency properties. If the molecular weight ofthe water-soluble polymer is too high, the resulting water-soluble filmdoes not maintain substantial transparency.

In one type of embodiment, a water-soluble film including a mixture ofPVOH (e.g., about 87.7% hydrolyzed) having a 4% solution viscosity ofabout 8 cps and 10 phr of sorbitol can demonstrate substantialtransparency for 30 days. In contrast, a water-soluble film including amixture of PVOH (about 87.7% hydrolyzed) having a viscosity of 23 cpsand 10 phr of sorbitol demonstrates substantial transparency for only 4days.

Water-soluble films of the present disclosure can include acompatibilizing agent for the sugar alcohol plasticizer that is a solidat room temperature. As used herein, a “compatibilizing agent” is acomponent that when included in the water-soluble film in a range ofabout 15 phr to about 20 phr (a ratio of about 2:1 to about 1:2 to thesugar alcohol plasticizer that is a solid at room temperature), resultsin the water-soluble film maintaining transparency at a sugar alcoholloading that would otherwise cause the water-soluble film to losetransparency. For example, a water-soluble film including acompatibilizing agent is able to maintain a Δ% opacity of 2.0% or lessfor a longer time period than an otherwise identical film that does notinclude the compatibilizing agent. The compatibilizing agent can beincluded in the water-soluble films of the present disclosure in a rangeof about 10 phr to about 25 phr, or in a range of about 13 phr to about22 phr, or in a range of about 15 phr to about 20 phr. As the amount ofcompatibilizing agent included in the water-soluble film is reduced, thewater-soluble film tends to lose transparency. As the amount ofcompatibilizing agent included in the water-soluble film is increased,the water-soluble film becomes more brittle and has slower dissolutiontimes.

Suitable compatibilizers include, but are not limited to, celluloseethers such as methylcellulose, hydroxypropyl methylcellulose,carboxymethyl cellulose, salts thereof, polysaccharides of pectin,polysaccharides of sodium alginate, modified starches such asacid-modified, hydroxypropylated starches (e.g., Pure-Cote B760 or B790available from Grain Processing Corporation, Muscatine, Iowa),hydroxyethyl starches (e.g., Ethylex 2035 available from Tate & LyleIngredients Americas LLC, 2200 E. Eldorado Street, Decater, Ill.) , andcombinations of any of the foregoing. In one class of embodiments, thecompatibilizer comprises sodium carboxymethyl cellulose (CMC). Thedegree of substitution of the CMC can be from about 0.60 to about 0.95,for example. As used herein, “degree of substitution” refers to thenumber of hydroxyl groups that have been substituted with a sodiumcarboxymethyl group (CH₂COO(Na)) per monomer unit. In one type ofembodiment, the viscosity of a 2% aqueous solution of CMC is in a rangeof about 20 to about 80 cP, as measured at 25° C. on a Brookfield LVTviscometer. In another class of embodiments, the compatibilizercomprises a hydroxypropylated starch. In one type of embodiment, thehydroxypropylated starch can have a 9.1% moisture content, a pH of about6.3, an ash content of 0.20 wt. % and a protein content of 0.173 wt. %.In another class of embodiments, the compatibilizing agent comprises ahydroxyethyl starch. The level of ethoxylation can be from about 2 wt. %to about 3 wt. %, for example, as the total weight of the substituentunits divided by the total weight of the polymer.

Water-soluble films according to the present disclosure further includesugar alcohol plasticizers that are solids at room temperature. Sugaralcohol plasticizers that are solid at room temperature include, but arenot limited to, isomalt, maltitol, sorbitol, xylitol, erythritol,adonitol, dulcitol, pentaerythritol, mannitol and combinations thereof.Suitable sugar alcohols are available from Rochem Intl. (Ronkonkoma,N.Y.), Roquette (Lestrem, France), and Sigma-Aldrich Co, LLC (St. Louis,Mo.).

Sugar alcohol plasticizers that are solid at room temperature can beincluded in the water-soluble films of the present disclosure in anamount in a range of about 5 phr to about 35 phr, or about 5 phr toabout 25 phr, or about 10 phr to about 25 phr, or about 10 phr to about25 phr, for example 10 phr, 15 phr, 20 phr, 25 phr, or 30 phr. A sugaralcohol plasticizer that is a solid at room temperature can be presentin the water-soluble films of the present disclosure in an amount suchthat the ratio of compatibilizing agent to sugar alcohol plasticizerthat is a solid at room temperature is in a range of about 2:1 to 1:2,for example about 2:1, about 1.9:1, about 1.8:1, about 1.7:1, about1.6:1, about 1.5:1, about 1.4:1, about 1.3:1, about 1.2:1, about 1.1:1,about 1:1, about 0.9:1, about 0.8:1, about 0.7:1, about 0.6:1 and/orabout 0.5:1. As the amount of sugar alcohol included in thewater-soluble film increases, the transparency of the water-soluble filmbecomes more negatively affected. As the amount of sugar alcoholincluded in the water-soluble film is reduced, the solubility of thewater-soluble film becomes negatively affected. That is, for example, ata constant temperature a film of equal thickness will take longer todissolve.

In one class of embodiments, the sugar alcohol plasticizer that is asolid at room temperature comprises two or more sugar alcoholplasticizers that are solids at room temperature. The two or more sugaralcohol plasticizers can be included in the film composition in anyrelative amounts. For example, the two or more sugar alcoholplasticizers can be included in the film composition in equal amounts,or one of the sugar alcohol plasticizers that is a solid at roomtemperature can be a minor impurity in another sugar alcohol plasticizeras provided by a commercial supplier. In another type of embodiment, thesugar alcohol plasticizer that is a solid at room temperature willinclude one that has a relatively high heat of fusion (e.g. above 247J/g, or above192 J/g) and a second one that has a relatively low heat offusion (e.g. 247 J/g or less, or 192 J/g or less, respectively).

In one class of embodiments, the sugar alcohol plasticizer that is asolid at room temperature is selected from the group consisting ofisomalt, maltitol, sorbitol, xylitol, adonitol, mannitol, andcombinations thereof, and further optionally the ratio ofcompatibilizing agent to sugar alcohol present in the water-soluble filmis about 2:1. As described below, water-soluble film according to thisclass of embodiments (including the described ratio of compatibilizingagent to sugar alcohol), cast to about 2.0 mils thick, maintained a Δ%opacity of 2.0% or less for at least 4 days longer than water-solublefilms of a similar composition except with no compatibilizing agentincluded, or at least 21 days longer, or at least 25 days longer.

In another class of embodiments, the sugar alcohol plasticizer that is asolid at room temperature is selected from the group consisting ofisomalt, maltitol, sorbitol, xylitol, adonitol, and combinationsthereof, and further optionally the ratio of compatibilizing agent tosugar alcohol present in the water-soluble film is less than 2:1.Water-soluble films according to this class of embodiments (includingthe described ratio of compatibilizing agent to sugar alcohol), cast toabout 2.0 mils thick, were shown to maintain a Δ% opacity of 2.0% orless for at least 12 days longer than water-soluble films of a similarcomposition except with no CMC included, or at least 19 days longer, orat least 23 days longer, or at least 28 days longer.

Unexpectedly, there was found to be no correlation between the number ofcarbons, molecular weight, or structure (linear vs cyclic or structuralisomers) of the sugar alcohol and the compatibilization of the sugaralcohol by the compatibilizing agent. That is, the transparencyenhancement of the water-soluble films that include the compatibilizingagent could not be predicted based on the number of carbons, molecularweight, or structure (linear vs. cyclic or structural isomers) of thesugar alcohol. As mentioned above, “enhanced transparency” as usedherein refers to a water-soluble film that demonstrates an opacity of37.0% or less as measured by a spectrophotometer, for example, 36.8% orless, or 36.6% or less. Unacceptable amounts of cloudiness of thewater-soluble film results when a water-soluble film has an opacity of37.2% or more, 37.3% or more, or 37.4% or more. More unexpectedly, theability of a given compatibilizing agent/sugar alcohol combination toresult in a water-soluble film with enhanced transparency (relative to afilm with the same sugar alcohol and no compatibilizing agent) can bepredicted based on the heat of fusion of the sugar alcohol. In one classof embodiments enhanced transparency is demonstrated when a sugaralcohol plasticizer that is a solid at room temperature characterized bya heat of fusion of about 247 J/g or less is included in a water-solublefilm in an amount of about 20 phr or less, with a compatibilizing agent.Suitable sugar alcohol plasticizers that demonstrate enhancedtransparency when included in a water-soluble film with acompatibilizing agent in an amount of about 20 phr or less can include,consist essentially of, or can consist of one or more of isomalt,maltitol, sorbitol, adonitol, and xylitol, and combinations thereof. Forexample, it was shown that a water-soluble film comprising 10 phr ofxylitol, having a heat of fusion of 247 J/g, demonstrated an opacity of36.6 after 30 days. In contrast, a water-soluble film comprising 10 phrof pentaerythritol, having a heat of fusion of 289 J/g, demonstrated anopacity of 38.6 after 30 days and had an undesirable cloudiness. Inanother, non-exclusive class of embodiments enhanced transparency isdemonstrated when a sugar alcohol plasticizer that is a solid at roomtemperature characterized by a heat of fusion of about 247 J/g or lessand has at least two adjacent, non sterically hindered hydroxyl groupsin a common plane is included in a water soluble film in an amount ofabout 20 phr or less. Without intending to be bound by theory, it isbelieved that the at least two sterically unhindered adjacent hydroxylgroups in a common plane favors the hydrogen bonding of the hydroxyls ofthe sugar alcohol with the hydroxyls of PVOH. Further, without intendingto be bound by theory, it is believed that the hydrogen bondinginteractions of the sugar alcohol with the PVOH stabilizes the sugaralcohols in the film formulation, allowing for a greater loading of thesugar alcohols characterized by a heat of fusion of 247 J/g or less. Inanother class of embodiments, enhanced transparency is demonstrated whena sugar alcohol plasticizer that is a solid at room temperaturecharacterized by a heat of fusion of about 192 J/g or less is includedin a water-soluble film in an amount of about 25 phr to about 35 phr, orabout 30 phr, with a compatibilizing agent. Suitable sugar alcoholplasticizers that demonstrate enhanced transparency when included in awater-soluble film with a compatibilizing agent in an amount of about 25phr to about 35 phr , or about 30 phr include, but are not limited to,isomalt, sorbitol, and combinations thereof. For example, it was shownthat a water-soluble film comprising 30 phr of sorbitol, having a heatof fusion of 192 J/g demonstrated an opacity of 35.7 after 30 days. Incontrast, a water-soluble film comprising 30 phr of adonitol, having aheat of fusion of 232 J/g, had an opacity of 42.4 after 30 days and hadan undesirable cloudy appearance. In another, non-exclusive class ofembodiments enhanced transparency is demonstrated when a sugar alcoholplasticizer that is a solid at room temperature characterized by a heatof fusion of about 192 J/g or less and has at least two adjacent, nonsterically hindered hydroxyl groups in a common plane is included in awater soluble film in an amount of about 25 phr to about 35 phr, forexample 30 phr. Without intending to be bound by theory, it is believedthat the at least two sterically unhindered adjacent hydroxyl groups ina common plane favors the hydrogen bonding of the hydroxyls of the sugaralcohol with the hydroxyls of PVOH. Further, without intending to bebound by theory, it is believed that the hydrogen bonding interactionsof the sugar alcohol with the PVOH stabilizes the sugar alcohols in thefilm formulation, allowing for a greater loading of the sugar alcoholscharacterized by a heat of fusion of 192 J/g or less.

In one class of embodiments, the water-soluble film includes a mixtureof PVOH, CMC, xylitol, and sorbitol. The CMC to xylitol ratio can be3:1, for example, while the ratio of compatibilizing agent to totalsugar alcohol plasticizer that is a solid at room temperature is in therange of about 2:1 to 1:2. Unexpectedly, a water-soluble film comprisinga 3:1 CMC to xylitol ratio demonstrated both favorable solubility andgood tear strength. As described above, when used herein, “favorablesolubility” refers to a film that, at about 2.0 mils thick, completelydissolves in less than 50 seconds, preferably less than 40 and mostpreferably less than 30 seconds in water at 23° C. As used herein, “goodtear strength” refers to a tear strength of at least 400 g/mil asmeasured by an Elmdorf Tearing Tester model number 40043, or equivalentas described in the Tear Strength Measurements section below.Surprisingly, a water-soluble film including a 3:1 ratio of CMC toxylitol had a faster rate of dissolution than a water-soluble filmincluding a CMC to xylitol ratio in which the xylitol is the majorcomponent. The rate of dissolution of the water-soluble film including a3:1 ratio of CMC to xylitol was also comparable to the rate at which awater soluble film of the same composition, except with no CMC,dissolves. The rate of dissolution of a water-soluble film comprisingCMC and xylitol would be expected to decrease when the amount of CMC inthe water-soluble film increased because CMC has a slower rate ofdissolution than xylitol.

More unexpectedly, a water-soluble film comprising a 3:1 ratio of CMC toxylitol demonstrates an increase in tear strength relative to awater-soluble film comprising either CMC or xylitol alone. Both CMC andxylitol are known to independently reduce the tear strength ofwater-soluble films comprised of PVOH. The inclusion of both componentsin a water-soluble film would be expected to compound the individualeffects, reducing the tear strength of a PVOH based water soluble filmcomprising to a level between the PVOH tear strength of a water-solublefilm with CMC only and the PVOH tear strength of a water-soluble filmwith only xylitol.

The water-soluble films according to the present disclosure may includeother optional additive ingredients including, but not limited to,plasticizers that are liquids at room temperature, surfactants, filmformers, antiblocking agents, internal release agents and otherfunctional ingredients, for example in amounts suitable for theirintended purpose.

Water is recognized as a very efficient plasticizer for PVOH and otherpolymers; however, the volatility of water makes its utility limitedsince polymer films need to have at least some resistance (robustness)to a variety of ambient conditions including low and high relativehumidity. Glycerin is much less volatile than water and has been wellestablished as an effective plasticizer for PVOH and other polymers.Glycerin or other such liquid plasticizers by themselves can causesurface “sweating” and greasiness if the level used in the filmformulation is too high. This can lead to problems in a film such asunacceptable feel to the hand of the consumer and even blocking of thefilm on the roll or in stacks of sheets if the sweating is not mitigatedin some manner, such as powdering of the surface. This could becharacterized as over plasticization. However, if too little plasticizeris added to the film the film may lack sufficient ductility andflexibility for many end uses, for example to be converted into a finaluse format such as pouches.

Plasticizers that are liquids at room temperature for use inwater-soluble films of the present disclosure include, but are notlimited to, glycerol, diglycerol, propylene glycol, ethylene glycol,diethyleneglycol, triethylene glycol, tetraethyleneglycol, polyethyleneglycols up to MW 400, 2 methyl 1, 3 propane diol, lactic acid andcombinations thereof. As less plasticizer is used, the film becomes morebrittle, whereas as more plasticizer is used the film loses tensilestrength. Plasticizers that are liquids at room temperature can beincluded in the water-soluble films in an amount in a range of about 25phr to about 50 phr, or from about 30 phr to about 45 phr, or from about35 phr to about 40 phr, for example.

Surfactants for use in water-soluble films are well known in the art.Optionally, surfactants are included to aid in the dispersion of thepolymer solution upon casting. Suitable surfactants for water-solublefilms of the present disclosure include, but are not limited to, dioctylsodium sulfosuccinate, lactylated fatty acid esters of glycerol andpropylene glycol, lactylic esters of fatty acids, sodium alkyl sulfates,polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80,lecithin, acetylated fatty acid esters of glycerol and propylene glycol,and acetylated esters of fatty acids, and combinations thereof. Thus,surfactants can be included in the water-soluble films in an amount ofless than about 2 phr, for example less than about 1 phr, or less thanabout 0.5 phr, for example.

A class of embodiments of the water-soluble films according to thepresent disclosure is characterized by the water-soluble film beingedible. In this class of embodiments the water-soluble polymers caninclude, can consist essentially of, or can consist of one or more ofPVOH, modified PVOH, water-soluble natural polymers including, but notlimited to, guar gum, xanthan gum, carrageenan, and starch,water-soluble polymer derivatives including, but not limited to,ethoxylated starch and hydroxypropylated starch, copolymers of theforgoing, and combinations of the forgoing. In one class of edibleembodiments, the water-soluble polymer is included in the filmcomposition in the lowest amount possible that will still allow theresulting film to demonstrate acceptable tear strength, solubility,tensile strength, elongation at break, and energy to break. Optionalingredients for inclusion in water-soluble films according to thedisclosure include one or more of plasticizers that are liquid at roomtemperature, surfactants, compatibilizers, co-polymers, and co-filmformers, for example. Liquid plasticizers can include, consistessentially of, or consist of one or more of glycerol, diglycerol,propylene glycol, low molecular weight polyethylene glycol (e.g., havinga liquid consistency, for example having a molecular weight such as 200,300, and 600), monoacetin, triacetin, triethyl citrate, and1,3-butanediol. Surfactants can include, consist essentially of, orconsist of dioctyl sodium sulfosuccinate, lactylated fatty acid estersof glycerol and propylene glycol, lactylic esters of fatty acids, sodiumalkyl sulfates, polysorbate 20, polysorbate 60, polysorbate 65,polysorbate 80, lecithin, acetylated fatty acid esters of glycerol andpropylene glycol, and acetylated esters of fatty acids, for example.Film formers can include, consist essentially of, or consist of one ormore of pullulan, pectin, starch, gelatin, sodium alginates and modifiedstarches. Other optional ingredients will be apparent to one of ordinaryskill in the art in view of the present disclosure. Components forinclusion in edible water soluble films can be those designated as“Generally Recognized as Safe” (GRAS) by the United States Food and DrugAdministration, and/or components with assigned, allowable E-numbers inthe European Union, and/or components that are not yet designated asGRAS or E-numbered but have gone through proper testing and have beendemonstrated as safe for human consumption in the amounts proposed foruse in the film.

Water-soluble films according to the present disclosure can be designedby the disclosure herein to demonstrate excellent practical toughness.As used herein, “excellent practical toughness” refers to one or more oftensile strength, elongation at break, and energy to break values thatfall within the ranges described herein, optionally a combination of allthree of tensile strength, elongation at break, and energy to breakvalues. Thus, according to this aspect of the invention thewater-soluble films according to the present disclosure can have atensile strength of at least about 10 N/mm², or greater than about 12N/mm², or greater than about 14 N/mm², or greater than about 16 N/mm² asmeasured on a Model 5543 Instron® Tensile Tester, or equivalent, asdescribed in the Tensile Strength Measurement section below. Thewater-soluble films according to this aspect of the invention can havean elongation at break value of at least about 250%, or greater thanabout 300%, or greater than about 350%, or greater than about 400% asmeasured on a Model 5543 Instron® Tensile Tester, or equivalent, asdescribed in the Tensile Strength Measurement section below. Thewater-soluble films according to this aspect of the invention can havean energy to break of at least about 0.5 J/mm², or greater than about1.0 J/mm², or greater than about 1.23 J/mm² as measured on a Model 5543Instron® Tensile Tester, or equivalent, as described in the TensileStrength Measurement section below. In one class of embodiments, awater-soluble film according to the disclosure includes PVOH, a CMCcompatibilizing agent and a combination of xylitol and sorbitol as thesugar alcohol plasticizer that is a solid at room temperature, with aCMC to sugar alcohol plasticizer ratio of about 1.1:1. Water-solublefilms according to this embodiment demonstrate good dissolution time at23° C., for example about 22.8 seconds, good tensile strength, forexample about 21.3 N/mm², good elongation to break, for example about467.3%, and good energy to break, for example about 1.7 J/mm². Inanother class of embodiments, a water-soluble film according to thedisclosure includes PVOH, a modified starch compatibilizing agent and acombination of xylitol and sorbitol as the sugar alcohol plasticizerthat is a solid at room temperature, with a compatibilizing agent tosugar alcohol plasticizer ratio of about 1.1:1. Water-soluble filmsaccording to this embodiment demonstrate good dissolution time at 23°C., for example about 31.4 seconds, good tensile strength, for exampleabout 19.6 N/mm², good elongation to break, for example about 497.7%,and good energy to break, for example about 1.5 J/mm².

The water-soluble films can be formed into a water-soluble packet.Packets may be made using any suitable equipment and method, includingthe various methods already commonly known in the art. The water-solublefilm optionally can be drawn into a suitable mold. Heat can be appliedto the water-soluble film during the process, to result in a processcommonly known as thermoforming. Water-soluble films according to thepresent disclosure are heat sealable. As used herein, “heat sealable”refers to films that when heat sealed at a temperature in a range ofabout 275° F. to about 300° F. (135° C. to about 150° C.) do not peelapart by hand without tearing the film and do not show any indicationsof degradation (i.e., browning or bubbling) when heat sealed in a TS-12Heat Sealer available from Lako Tool & Manufacturing, Inc of Perrysburg,Ohio, or equivalent, as described in the Heat Seal Measurements sectionbelow. In one class of embodiments, the heat sealable water-solublefilms have a peak load ratio (i.e. a ratio of the seal peak load to thefilm peak load) of at least about 0.30, at least about 0.32, at leastabout 0.35, or at least about 0.36 as determined by measurements takenon a Model 5543 Instron® Tensile Tester, or equivalent, as described inthe Tensile Strength Measurement section below. Water-soluble filmsaccording to the present disclosure are thermoformable. As used herein,“thermoformable” refers to a water soluble film that has an elongationat about 23° C. and 35% relative humidity of at least about 250%, or atleast about 300% and is heat stable.

Specific contemplated aspects of the disclosure are herein described inthe following numbered paragraphs.

1. A water soluble film, comprising a water soluble mixture of

-   -   a water soluble resin,    -   a compatibilizing agent, and    -   a sugar alcohol plasticizer that is a solid at room temperature,    -   wherein the water soluble film is substantially transparent.

2. The water soluble film of paragraph 1, wherein the sugar alcoholplasticizer is included in an amount of about 20 phr or less and ischaracterized by a heat of fusion of about 247 J/g or less.

3. The water soluble film of paragraph 1, wherein the sugar alcoholplasticizer is included in an amount of about 25 to about 35 phr and ischaracterized by a heat of fusion of about 192 J/g or less.

4. A water soluble film, comprising a water soluble mixture of

-   -   a water soluble resin,    -   a compatibilizing agent,    -   xylitol, and    -   a second sugar alcohol plasticizer that is a solid at room        temperature,    -   wherein the water soluble film of about 2.0 mils thick dissolves        in less than 50 seconds, preferably less than 40 and most        preferably less than 30 at 23° C., and    -   wherein the compatibilizing agent is carboxymethyl cellulose.

5. The water soluble film according to any of the preceding paragraphs,wherein the sugar alcohol plasticizer is a combination of at least twoor more sugar alcohol plasticizers that are solid at room temperature.

6. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble film has a tear strength of atleast 400 g/mL.

7. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble film is substantially transparent.

8. The water soluble film according to any one of paragraphs 4-7,wherein the ratio of compatibilizing agent to xylitol is about 3:1.

9. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble film is edible.

10. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble resin is selected from the groupconsisting of polyvinyl alcohol, modified polyvinyl alcohols,water-soluble natural polymers including, guar gum, xanthan gum,carrageenan, and starch, water-soluble polymer derivatives including,ethoxylated starch and hydroxypropylated starch, copolymers of theforgoing, or any combination of the forgoing.

11. The water soluble film according to paragraph 10, wherein the watersoluble resin comprises polyvinyl alcohol.

12. The water soluble film according to paragraph 10, wherein the watersoluble resin comprises polyvinyl alcohol with a degree of hydrolysis ina range of about 75% to about 99%.

13. The water soluble film according to paragraph 10, wherein thepolyvinyl alcohol is further characterized by a weight average molecularweight in a range of about 55, 000 to about 80,000.

14. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble resin is included in the film inan amount in a range of about 35 to about 90 wt. %, based on the totalweight of the film.

15. The water soluble film according to any one of the precedingparagraphs, wherein the sugar alcohol plasticizer that is a solid atroom temperature is included in the film an amount in a range of about 5to about 35 parts per hundred parts resin (phr).

16. The water soluble film according to any one of paragraphs 4-16,wherein the sugar alcohol plasticizer that is a solid at roomtemperature, or mixtures thereof, is characterized by a heat of fusionof less than about 274 J/g.

17. The water soluble film according to any one of paragraphs 4-17,wherein the sugar alcohol plasticizer that is a solid at roomtemperature, or mixtures thereof, is characterized by a heat of fusionin a range of less than about 192 J/g.

18. The water soluble film according to any one of the precedingparagraphs, wherein the sugar alcohol plasticizer that is a solid atroom temperature is selected from the group consisting of isomalt,maltitol, sorbitol, adonitol, xylitol, and combinations of any of theforgoing.

19. The water soluble film according to any one of the precedingparagraphs, wherein the sugar alcohol plasticizer that is a solid atroom temperature comprises a mixture of xylitol with at least one memberof the group consisting of maltitol, sorbitol, and isomalt.

20. The water soluble film according to any one of the precedingparagraphs, wherein the compatibilizing agent is selected from the groupconsisting of a cellulose ether, modified starch, polysaccharides ofpectin, polysaccharides of sodium alginate, or combinations thereof.

21. The water soluble film according to paragraph 20, wherein thecellulose ether comprises carboxymethyl cellulose.

22. The water soluble film according to paragraph 21, wherein thecarboxymethyl cellulose has a degree of substitution in a range of about0.6 to about 0.95.

23. The water soluble film according to any one of the precedingparagraphs, wherein the compatibilizing agent is included in the film inan amount in a range of about 10 to about 25 phr.

24. The water soluble film according to any one of the precedingparagraphs, wherein the ratio of compatibilizing agent to sugar alcoholplasticizer that is a solid at room temperature is about 2:1 to about1:2.

25. The water soluble film according to any one of the precedingparagraphs, further comprising a liquid plasticizer selected from thegroup consisting of glycerol, diglycerol, propylene glycol, ethyleneglycol, diethyleneglycol, triethylene glycol, tetraethyleneglycol,polyethylene glycols up to MW 400, 2 methyl 1,3 propane diol andcombinations of the forgoing.

26. The water soluble film according to paragraph 25, wherein the liquidplasticizer is present in the film an amount in a range of about 25 toabout 50 phr.

27. The water soluble film according to any one of the precedingparagraphs, further comprising a surfactant.

28. The water soluble film according to paragraph 27, wherein thesurfactant is selected from the group consisting of dioctyl sodiumsulfosuccinate, lactylated fatty acid esters of glycerol and propyleneglycol, lactylic esters of fatty acids, sodium alkyl sulfates,polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80,lecithin, acetylated fatty acid esters of glycerol and propylene glycol,and acetylated esters of fatty acids, and combinations of any of theforgoing.

29. The water soluble film according to paragraph 27, wherein thesurfactant is present in the film an amount in of less than about 2 phr.

30. The water soluble film according to any one of the precedingparagraphs, wherein the water soluble film is characterized by a tearresistance of at least 500 g/mil.

31. The water soluble film according to any one of the precedingparagraphs, wherein the film is heat sealable.

32. The water soluble film of paragraph 31, wherein the film isthermoformable.

33. The water soluble film of paragraph 31, wherein the film has a peakload ratio of at least about 0.30.

34. The water soluble film according to any one of the precedingparagraphs, wherein the film has a tensile strength of at least 10N/mm².

35. The water soluble according to any one of the preceding paragraphs,wherein the film has an elongation at break of at least 250%.

36. The water soluble film according to any one of the precedingparagraphs, wherein the film has an energy break of at least 0.5 J/mm².

37. The water soluble film according to any one of the precedingparagraphs, wherein the film maintains a Δ% opacity of 2.0% or less forat least 4 days longer than an otherwise identical film having nocompatibilizing agent.

38. A water soluble packet, comprising a film according to any one ofthe preceding paragraphs.

EXAMPLES Transparency Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thicknesses to determine if the film turnscloudy. These experiments were performed with and without carboxymethylcellulose (CMC). All film samples were hung in a lab environment set tooperate at 23° C.+/−3 ° C. (73° F.+/−5 ° F.) with an observed range of20° C.-26° C. (66° F.-78° F.). The relative humidity of the lab was setto 50% +/−5% with an observed range of 30%-60% RH (RH=relativehumidity). Each film was observed every four days plus or minus a dayfor a two week minimum.

The films were tested for a change in the percent opacity by an X-RITESP60 Series Sphere Spectrophotometer X-64 colorimeter, available fromX-Rite Incorporated, Grand Rapids, Michigan. The spectrophotometer wascalibrated using X-Rite Calibration Standard SP62-162 (L*05.17, a*−1.16,B* −0.20). A 5″ by 5″ square of Mylar (approximately 4.75 mil gauge) wascut and the average opacity was determined to be 18.61 by thespectrophotometer. Five 1″ by 1″ squares were drawn on the Mylar squareswith a fine tip marker according to the drawings in FIGS. 1(a) and 1(b).Samples of film were fixed to the Mylar template using ¾″ binder clipsand the film samples were each labeled according to their identifyingformula.

Non-powdered moisture barrier gloves were used when handling the filmsamples to mitigate moisture contamination of the film samples. Moisturecontamination may cause unnatural cloudiness in the film. The films werecast to a nominal 2.0 mil gauge. The samples were cast in ambientconditions and initial data was measured in the ambient environmentprior to placement in the testing environment of nominally 23 ° C.+/−3 °C. (73 ° F.+/−5 ° F.), and 50% RH +/−5% RH. For conditioning of thefilm, the ¾″ binder clips holding the test sample were clipped to a coathanger using 1-¼″ binder clips and hung from a the coat hanger in thespecified conditioning environment. Film was mixed on a Monday, cast ona Tuesday, and hung in set environment on Wednesday (t=0). Film wasmeasured every Monday, Wednesday, and Friday (t=0, 2, 5, 7, 9, 12, 14,16, 19, 21, 23, 26, 28, 30) until 30 days of measurement and observationwas achieved.

The colorimeter was set to: number of average readings N =2, Lab, SPIN,and illuminant of D65/10. The Opacity test was selected from thespectrophotometer menu. A double Mylar standard (two plies of 4.75 milMylar film over white portion of a Leneta chart 7-⅝″×10¼″ 2C B#42201)was loaded into the spectrophotometer. For each of the five spotsdesignated on the film sample swatch, a piece of Mylar film was selectedfor backing and clipped to the back of the sample being measured. Thesample was placed over the black portion of the Leneta chart. When thesample was flat against the Leneta chart and the sample itself was flatbetween the front and back sheets of Mylar, two sample measurements weretaken. The sample was moved to the white portion of the Leneta chart andwhen the sample was flat against the Leneta chart and flat between thetwo sheets of Mylar, two samples measurements were taken. A reading ofthe white portion of the Leneta chart, without the samples. For eachmeasurement, the % Opacity, L, a, b, and E values that were displayed onthe screen were recorded. After measurement, the samples were returnedto the conditioning environment. The film opacity is reported as thenumber of days the Δ% Opacity was 2% or less, i.e., the number of daysthe difference in opacity between the tested film and the t=0 film was2% or less.

Tear Strength Measurements

This method covers the determination of the average force in grams permil of specimen thickness required to propagate tearing through aspecified length of polyvinyl alcohol (PVOH) film. The force in gramsrequired to propagate tearing across a film is measured using aprecisely calibrated pendulum device. Acting by gravity, the pendulumswings through an arc, tearing the specimen from a pre-cut slit. Thespecimen is held stationary on one side and on the other is fixed to thependulum. The loss of energy of the pendulum swing is indicated by apointer on a scale. The scale indication is a function of the forcerequired to tear the specimen. This method is of value in rankingrelative tearing resistance of PVOH films. The water-soluble films wereevaluated on an Elmendorf Tearing Tester Model # 40043, in accordancewith MSTM 107RD Standard Test Method for Propagation Tear Resistance ofPolyvinyl Alcohol Film.

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thicknesses. These experiments were performedwith and without carboxymethyl cellulose (CMC). The water-soluble filmswere conditioned at a temperature of about 23 ° C.+/−3 ° C. (73° F.+/−5°F.) and relative humidity of about 35% ±5% for not less than 8 hoursprior to the test. The tests were conducted in the standard laboratoryatmosphere of a temperature of 23° C.+/−3° C. (73° F.+/−5° F.) and arelative humidity of 35% ±5%. The average tearing force in grams-forceper MIL was calculated as follows:

${{Tearing}\mspace{14mu}{force}},{{g/{mil}} = \frac{\left( {{Augmenting}\mspace{14mu}{Weight}\mspace{14mu}{g/100}} \right) \times {scale}\mspace{14mu}{reading}}{{Film}\mspace{14mu}{thickness}\mspace{14mu}{is}\mspace{14mu}{MIL}}}$

Solubility Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thicknesses. Test specimens were cut from filmsamples (i.e., about 3.8 cm×3.2 cm specimen). If cut from a film web,specimen was cut from areas of web approximately evenly spaced along thetransverse direction of the web. Each specimen was locked in a separate35 mm slide mount.

For each specimen, a beaker was filled with 500 mL of distilled water.The water temperature was measured with a thermometer and, if necessary,heated or cooled to maintain temperature at 10 ° C. or 23° C. The heightof column of water was marked, and a magnetic stirring rod was added tothe beaker. The stir speed was adjusted until a vortex approximatelyone-fifth the height of the water column developed. The depth of thevortex was marked.

The 35 mm slide mount was secured to a 35 mm slide mount holder suchthat the long end of the slide mount was parallel to the water surface.The depth adjuster of the holder was set so that when dropped, the endof the clamp was 0.6 cm below the surface of the water. One of the shortsides of the slide mount was positioned next to the side of the beakerwith the other positioned directly over the center of the stirring rodsuch that the film surface was perpendicular to the flow of the water.

In one motion, the secured slide was dropped and clamped into the waterand the timer was started. Disintegration occurred when the film brokeapart. When all visible film was released from the slide mount, theslide was raised out of the water while the solution was monitored forundissolved film fragments. Dissolution occurred when all film fragmentswere no longer visible and the solution became clear.

Tensile Strength Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thickness. Samples were about 1.0 inches (2.5cm) wide and about 3 inches (7.6 cm) long with the long dimension in themachine (casting) direction. The tests were conducted in the standardlaboratory atmosphere of a temperature of 23° C.+/−3° C. (73° F.+/−5°F.) and a relative humidity of 35%±5%. The ultimate tensile strength wasmeasured utilizing the ASTM D 882, “Standard Test Method for TensileProperties of Thin Plastic Sheeting.” The test was conducted on a Model5543 Instron® Tensile Tester in a laboratory after aging at least about12 hours. Without intending to be bound by any particular theory, it isbelieved that the Instron® grips utilized in the test may affect thetest results. Consequently, the test was conducted utilizing Instron®grips having model number 2702-032 faces, which are rubber coated and 25mm wide. Values were obtained directly from the Instron® Bluehillsoftware version 2.25.796.

Elongation at Break Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thickness. Samples were about 1.0 inches wideand at least about 3 inches long with the long dimension in the machine(casting) direction. The tests were conducted in the standard laboratoryatmosphere of a temperature of 23° C.+/−3° C. (73° F.+/−5° F.) and arelative humidity of 35%±5%. The elongation to break of a film wasmeasured utilizing the ASTM D 882, “Standard Test Method for TensileProperties of Thin Plastic Sheeting.” The test was conducted on a Model5543 Instron® Tensile Tester in a laboratory conditioned after aging atleast about 12 hours. Without intending to be bound by any particulartheory, it is believed that the Instron® grips utilized in the test mayaffect the test results. Consequently, the test was conducted utilizingInstron® grips having model number 2702-032 faces, which are rubbercoated and 25 mm wide. Values were used directly from the Instron®Bluehill software version 2.25.796.

Energy to Break Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 2.0 mil thickness. Samples were about 1.0 inches wideand about 3 inches long with the long dimension in the machine (casting)direction. The tests were conducted in the standard laboratoryatmosphere of a temperature of 23° C.+/−3° C. (73° F.+/−5° F.) and arelative humidity of 35% ±5%. The energy to break of a film at wasmeasured utilizing the ASTM D 882, “Standard Test Method for TensileProperties of Thin Plastic Sheeting.” The test was conducted on a Model5543 Instron® Tensile Tester in a laboratory after aging at least about12 hours. Without intending to be bound by any particular theory, it isbelieved that the Instron® grips utilized in the test may affect thetest results. Consequently, the test was conducted utilizing Instron®grips having model number 2702-032 faces, which are rubber coated and 25mm wide. Values were used directly from the Instron® Bluehill softwareversion 2.25.796 for the Energy/Area methodology.

Heat Seal Measurements

Various sugar alcohols were added to polyvinyl alcohol formulations andcast at nominally 1.5 mil thickness. Samples were about 1.0 inches (2.5cm) wide and about 3 inches (7.6 cm) long with the long dimension in themachine (casting) direction. The tests were conducted in the standardlaboratory atmosphere of a temperature of 23° C.+/−3° C. (73° F.+/−5°F.) and a relative humidity of 35% ±5%. The peak load for tensile modefailure for the samples was determined (i.e., the film peak load) on aModel 5543 Instron® Tensile Tester. Samples were then heat sealed at aseries of temperatures at 22 psi (152 kPa) and a dwell time of 1 secondin a TS-12 Heat Sealer available from Lako Tool & Manufacturing, Inc ofPerrysburg, OH. At temperatures below about 275° F. (135° C.) the sealswere found to peel apart without the film tearing during handinspection. At temperatures above 300° F. (149° C.) the films began toturn brown and bubbling occurred, indicating the onset of degradation.Therefore, a temperature ladder from 275° F. to 300° F. (135° C. to 149°C.)in 5° F. (about 3° C.) increments was conducted. The sealed films foreach temperature setting were then tested in the tensile mode on a Model5543 Instron® Tensile Tester and the seal peak load was recorded. Theratio of the seal peak load divided by the film peak load was reportedas the peak load ratio.

Example 1

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 1 2 3 4 5 6 PVOH 8 cps, 88% DH 100 100 100 100 100100 Xylitol Sugar alcohol 0.00 11.10 22.22 33.33 44.45 0.00 plasticizersolid at RT CMC 1 Compatibilizing 44.45 33.33 22.22 11.10 0.00 0.00agent Sorbitol Sugar alcohol 7.90 7.90 7.90 7.90 7.90 5.47 plasticizersolid at RT Glycerol, Liquid plasticizer 63.95 63.95 63.95 63.95 63.9544.27 Propylene Glycol Process Aids surfactant 2.54 2.54 2.54 2.54 2.541.76 CMC 1 Carboxymethyl cellulose characterized by a 2% solutionviscosity at 25° C. of 25-50 cP and a degree of substitution of 0.65 to0.90

Water-soluble films 1-5 were each comprised of 45 wt % PVOH, based onthe total weight of the film. 20 wt % of the films were comprised of acombination of CMC and xylitol. Water-soluble film 6 contained 65 wt %PVOH with no CMC or xylitol, as a control film. The relative amounts ofCMC and xylitol were varied over films 1-5. 2.0 mil thick water-solublefilms were cast according to formulae 1-5, conditioned for 24 hours, andwere tested for tear strength, solubility, tensile strength, elongationat break, and energy to break, as described above. The results arereproduced in the table below.

Property 1 2 3 4 5 6 Tear Strength MD (g/mil) 8 634 413 137 217 1341Dissolution at 10° C. (s) 20.9 16.6 20.7 25.7 14.9 26.4 Dissolution at23° C. (s) 17.4 8.7 16.9 18.2 10.1 17.9 Tensile Strength (N/mm²) 17.510.9 13.1 15.7 8.5 18.2 Elongation at break (%) 118.4 600.4 430.8 419.6550.2 535.6 Energy to break (J/mm²) 0.4 1.1 1.0 1.2 0.9 1.5

FIG. 2 is a plot of the tear strengths vs. the wt % xylitol included inthe water-soluble films. FIG. 3 is a plot of dissolution times vs. thewt % xylitol included in the water-soluble films. FIG. 4 is a contourplot of the tear strengths of PVOH based water-soluble films withdifferent loadings of CMC and xylitol. As expected, the water-solublefilm containing PVOH and CMC with no xylitol, film 1, was found to bebrittle and dissolve relatively slowly at 23° C., relative to thecontrol film 6. This film did show some improved dissolution propertiesat 10° C. Film 5, the other extreme, containing PVOH and xylitol with noCMC also was found to have decreased tear strength relative to thecontrol film 6, and increased rate of dissolution, as expected.Unexpectedly, when the CMC and xylitol were both included, in a ratio ofabout 3:1 respectively (film 2), the tear strength was found to behigher than the tear strength of either film 1 or film 5; however asexpected, the tear strength was still less than that of the control film6. Also surprisingly, film 2 had the fastest rate of dissolution out ofall the films except the xylitol-only film (film 5), which had similarrates of dissolution. This is unexpected because in film 2, CMC is themajor component of the CMC/xylitol mixture, and the rate of dissolutionwould be expected to decrease, that is a film of given thickness wouldbe expected to take longer to dissolve with the higher level of CMC.

Example 2

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 7 8 PVOH 8 cps, 88% DH M_(w) 100 0 about 67,000PVOH 23 cps, 88% DH M_(w) 0 100 about 160,000 Sorbitol Sugar alcoholplasticizer 10.00 10.00 solid at RT Glycerol, Liquid Plasticizer 31.3031.30 Propylene Glycol Process Aids Surfactant 1.20 1.20

2.0 mil thick water-soluble films were cast according to formulae 7 and8, were conditioned for 24 hours, and the transparency behavior of thewater-soluble films was monitored. The water-soluble film containing thelow molecular weight polyvinyl alcohol, film 7, maintained a Δ% Opacityof 2.0% or less for less than 9 days. In contrast, the water-solublefilm containing the high molecular weight polyvinyl alcohol, film 8,only maintained a Δ% Opacity of 2.0% or less for less than 2 days.

Example 3

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 9 10 11 12 13 14 PVOH 8 cps 88% DH 100 100 100 100100 100 CMC 2 Compatibilizing 18.13 0 18.13 0 18.13 0 agent SorbitolSugar alcohol 10.00 10.00 20.00 20.00 30.00 30.00 plasticizer solid atRT Glycerol, Liquid Plasticizer 36.98 31.30 36.98 31.30 36.98 31.30Propylene Glycol Process Aid Surfactant 1.42 1.20 1.42 1.20 1.42 1.20CMC 2 Carboxymethyl cellulose characterized by a 2% solution viscosityof 20 to 50 cP at 25° C. and a degree of substitution of 0.70 to 0.85

2.0 mil thick water-soluble films were cast according to formulae 9-14,conditioned for 24 hours, and the transparency behavior of thewater-soluble films was monitored. The number of days until a film had aΔ% Opacity of greater than 2% was recorded. The results are reproducedin the table below.

9 10 11 12 13 14 Sorbitol 10.00 10.00 20.00 20.00 30.00 30.00 loading(phr) CMC Yes No Yes No Yes No included Days until 30 days 9 days 30days 7 days 30 days 5 days Δ% Opacity is greater than 2.0

The water-soluble films that contained CMC, films 9, 11 and 13maintained substantial transparency for at least 30 days. However, films10, 12, and 14 that did not contain CMC became more opaque quickly. Asthe loading of sorbitol increased the films without CMC became moreopaque at increasingly faster rates. At a sorbitol loading of 10 phr thefilm (film 10) without CMC remained substantially transparent less than9 days. At a sorbitol loading of 20 phr the film (film 12) remainedsubstantially transparent for less than 7 days, and when the sorbitolloading was increased further, to 30 phr, the film (film 14) turnedopaque much more quickly, after less than 4 days. When CMC was presentin the films, the film containing 10 phr sorbitol (film 9), the filmcontaining 20 phr sorbitol (film 11) and the film containing 30 phrsorbitol (film 13) remained substantially transparent for at least 30days. Water-soluble films that contained sorbitol demonstrated poortransparency without CMC at even low sorbitol loadings, and theperformance was improved with the introduction of CMC into the film,especially at high sorbitol loadings.

Example 4

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 15 16 17 18 19 20 PVOH 8 cps, 88% DH 100 100 100100 100 100 CMC 2 Compatibilizing 18.13 0 18.13 0 18.13 0 agent MaltitolSugar alcohol 10.00 10.00 20.00 20.00 30.00 30.00 plasticizer solid atRT Glycerol, Liquid Plasticizer 36.98 31.30 36.98 31.30 36.98 31.30Propylene Glycol Process Aid Surfactant 1.42 1.20 1.42 1.20 1.42 1.20

2.0 mil thick water-soluble films were cast according to formulae 15-20,conditioned for 24 hours, and the transparency behavior of thewater-soluble films was monitored. The number of days until a film had aΔ% Opacity of greater than 2% was recorded. The results are reproducedin the table below.

15 16 17 18 19 20 Maltitol 10.00 10.00 20.00 20.00 30.00 30.00 loading(phr) CMC Yes No Yes No Yes No included Days until 30 days 5 days 28days 2 days 21 days 2 days Δ% Opacity is greater than 2.0

The water-soluble films that contained 10, phr of maltitol and no CMC,film 16, remained substantially transparent for only 5 days. When themaltitol loading was increased further to 20 and 30 phr, films 18 and20, the films became opaque much more quickly, after less than 2 days.However, the films that contained CMC remained substantially transparentfor up to 30 days when the maltitol loading was 10, 28 days when themaltitol loading was 20 phr and 21 days when the maltitol loading was 30phr. Although maltitol is a disaccharide consisting of a linear and acyclic unit, films that included maltitol had similar transparencyproperties as films that included the linear monosaccharide, sorbitol.As in the case with sorbitol, Example 3, the inclusion of CMC in thefilms that included maltitol resulted in an increase in the number ofdays that the films remained substantially transparent.

Comparative Example 5

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 21 22 23 24 25 26 PVOH 8 cps, 88% DH 100 100 100100 100 100 CMC 2 Compatibilizing 18.13 0 18.13 0 18.13 0 agent MannitolSugar alcohol 10.00 10.00 20.00 20.00 30.00 30.00 plasticizer solid atRT Glycerol, Liquid Plasticizer 36.98 31.3 36.98 31.3 36.98 31.3Propylene Glycol Process Aid Surfactant 1.42 1.20 1.42 1.20 1.42 1.20

2.0 mil thick water-soluble films were cast according to formulae 21-26,conditioned for 24 hours, and the transparency behavior of thewater-soluble films was monitored. The number of days until a film had aΔ% Opacity of greater than 2% was recorded. The results are reproducedin the table below.

21 22 23 24 25 26 Mannitol 10.00 10.00 20.00 20.00 30.00 30.00 loading(phr) CMC included Yes No Yes No Yes No Days until Δ% 9 days 2 days 2days 2 days 2 days 2 days Opacity is greater than 2.

Mannitol, (2R,3R,4R,5R)-hexan-1,2,3,4,5,6-hexol, is a stereoisomer ofsorbitol, (2S,3R,4R,5R)-hexan-1,2,3,4,5,6-hexol. However, unlike thewater-soluble films that included sorbitol (Example 3), water-solublefilms that included mannitol only remained substantially transparent for9 days, regardless of the loading level of mannitol, or the inclusion ofCMC. Although mannitol and sorbitol are both six carbon, linear sugarsof equal molecular weight, the heats of fusion of the two sugar alcoholplasticizers that are solids at room temperature are not similar.Sorbitol has a heat of fusion of 192 J/g and mannitol has a heat offusion of 301 J/g.

Example 6

A set of water-soluble films were prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 27 28 29 30 31 32 PVOH 8 cps, 88% DH 100 100 100100 100 100 CMC 2 Compatibilizing 18.13 0 18.13 0 18.13 0 agent XylitolSugar alcohol 10.00 10.00 20.00 20.00 30.00 30.00 plasticizer solid atRT Glycerol, Liquid plasticizer 36.98 31.3 36.98 31.3 36.98 31.3Propylene Glycol Process Aid Surfactant 1.42 1.20 1.42 1.20 1.42 1.20

2.0 mil thick water-soluble films were cast according to formulae 27-32,conditioned for 24 hours, and the transparency behavior of thewater-soluble films was monitored. The number of days until a film had aΔ% Opacity of greater than 2% was recorded. The results are reproducedin the table below.

27 28 29 30 31 32 Xylitol 10.00 10.00 20.00 20.00 30.00 30.00 loading(phr) CMC Yes No Yes No Yes No included Days until 30 days 26 days 30days 2 days 14 days 2 days Δ% Opacity is greater than 2.

The water-soluble film that contained 10 phr of xylitol and no CMC, film28, remained substantially transparent for 26 days. When the xylitolloading was increased to 20 or 30 phr, films 30 and 32, the films becameopaque much more quickly, after 2 days. However, the films that includedCMC were substantially transparent for up to 30 days, 30 days and 14days at xylitol loadings of 10, 20, and 30 phr, respectively. Althoughxylitol is a five carbon sugar alcohol plasticizer, the water-solublefilms that include xylitol behaved similar to the water-soluble filmsthat contained the six carbon sugar alcohol plasticizer, sorbitol. As inthe case with sorbitol, Example 3, the inclusion of CMC in the filmsthat included xylitol resulted in an increase in the number of days thatthe films remained substantially transparent.

Example 7

An edible water-soluble film was prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 33 PVOH 8 cps, 88% DH 100 CMC 2 Compatibilizingagent 17.04 Xylitol Sugar alcohol plasticizer 8.52 solid at RT SorbitolSugar alcohol plasticizer 4.57 solid at RT Glycerol, Liquid Plasticizer36.98 Propylene glycol Process aid Surfactant 1.43

2.0 mil thick water-soluble films were cast according to formula 33,conditioned for 24 hours, and were tested for tear strength, solubility,tensile strength, elongation at break, and energy to break as describedabove. The results are reproduced in the table below.

Property 33 Tear Strength MD (g/mil) 51 Dissolution at 10° C. (s) 46.5Dissolution at 23° C. (s) 22.8 Tensile Strength (N/mm²) 21.3 Elongationat break (%) 467.3 Energy to break (J/mm²) 1.7

Example 7 demonstrates an edible water soluble film according to theinvention that has good dissolution time, tensile strength, elongationat break and energy to break. Example 7 includes a cellulose ether as acompatibilizing agent.

Example 8

An edible water-soluble film was prepared with the ingredientsidentified below in the amounts shown (phr).

Component Description 34 PVOH 8 cps, 88% DH 100 Modified StarchCompatibilizing agent 17.04 Pure Cote B790 Xylitol Sugar alcoholplasticizer 8.52 solid at RT Sorbitol Sugar alcohol plasticizer 4.57solid at RT Glycerol, Liquid Plasticizer 36.98 Propylene Glycol ProcessAid Surfactant 1.35

2.0 mil thick water-soluble films were cast according to formula 34,conditioned for 24 hours, and were tested for tear strength, solubility,tensile strength, elongation at break, and energy to break as describedabove. The results are reproduced in the table below.

Property 34 Tear Strength MD (g/mil) 869 Dissolution at 10° C. (s) 69.9Dissolution at 23° C. (s) 31.4 Tensile Strength (N/mm²) 19.6 Elongationat break (%) 497.7 Energy to break (J/mm²) 1.5

Example 8, like Example 7, demonstrates an edible water soluble filmaccording to the invention that has good dissolution time, tensilestrength, elongation at break and energy to break. Example 8 includes amodified starch as a compatibilizing agent.

Example 9

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 35 PVOH 8 cps, 88% DH 100 CMC 2 Compatibilizingagent 18.13 Xylitol Sugar alcohol plasticizer, 18.13 solid at RTSorbitol Sugar alcohol plasticizer, 4.57 solid at RT Glycerol, LiquidPlasticizer 36.98 Propylene Glycol Process Aid Surfactant 1.46

Water-soluble packets were made from the water-soluble film according toformula 35. The water-soluble film of the packets had an averagethickness of 1.52 mils. Oatmeal was enclosed within the packets. Thecompatibility of the packets with the oatmeal was tested under threetest atmospheres for 42 days. The packets were inserted into highdensity polyethylene (HDPE) jars and capped, and subjected to one ofeither: ambient temperature and humidity (about 23° C. and about 30 to50% relative humidity (RH)); 38° C. and about 80% RH; or 38° C. andabout 10% RH.

After 42 days, the exposed packets were tested against unexposed film offormula 35. Inspection of the exposed packets revealed no visible filmor product discoloration, or packet adhesiveness when stored in HDPEjars. Flexibility appeared unchanged. Solubility tests were conductedand no increased time was required for complete solubility as a resultof product storage within test environments. The elongation values ofthe packets were tested against unexposed film. Under all testenvironments, the elongation values of the packets were slightly reducedwhen compared to the unexposed film. The results are reproduced in thetable below.

Elongation Complete Dissolution Time (s) at Break (%) At 30° C. and 1.5mils thick Unexposed 528 15 42 days @ 23° C., 384 14 30 to 50% RH 42days @ 38° C., 369 15 80% RH 42 days @ 38° C., 339 16 10% RH

Example 10

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 36 15 9 37 27 38 39 40 21 PVOH 8 cps 88% DH 100100 100 100 100 100 100 100 100 CMC 2 Compatibilizing 18.13 18.13 18.1318.13 18.13 18.13 18.13 18.13 18.13 agent Variable Sugar alcohol 10.0010.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 (See the plasticizersolid table below) at RT Glycerol, Liquid 36.98 36.98 36.98 36.98 36.9836.98 36.98 36.98 36.98 Propylene Plasticizer Glycol Process AidSurfactant 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42

2.0 mil thick water-soluble films were cast according to formulae 36,15, 9, 37, 27, 38-40, and 21, conditioned for 24 hours, and thetransparency behavior of the water-soluble films was monitored. Thetransparency of the films was monitored for 30 days with exception oferythritol (formula 39), 26 days, and mannitol (formula 21), 21 days.The results are reproduced in the table below.

Sugar Alcohol Opacity at Heat of Formulae Sugar Alcohol Loading (phr) 30days Fusion (J/g) 36 Isomalt 10 35.8 142 15 Maltitol 10 35.8 164 9Sorbitol 10 35.9 192 37 Adonitol 10 36.3 232 27 Xylitol 10 36.5 247 38Dulcitol 10 37.2 340 39 Erythritol 10 37.9 329 40 Pentaerythritol 1038.6 289 21 Mannitol 10 39.2 301

Films according to formulae 38, 39, 40, and 21 having the describedamounts of dulcitol, erythritol, pentaerythritol or mannitol as thesugar alcohol plasticizer that is a solid at room temperaturedemonstrated an undesirable cloudiness. In contrast, films according toformulae 36, 15, 9, 37, and 27 comprising isomalt, maltitol, sorbitol,or adonitol as a sugar alcohol plasticizer that is solid at roomtemperature demonstrated an acceptable level of transparency. Theundesirable films had opacity values of 37.2% or greater while thedesirable films had opacity levels of 36.6% or less. Example 10 showsthat in films comprising 10 phr of the sugar alcohol plasticizer that isa solid at room temperature, films wherein the sugar alcohol plasticizerhad a heat of fusion of about 247 J/g or less were acceptablytransparent and films wherein the sugar alcohol plasticizer had a heatof fusion of about 289 J/g or greater at these loading rates hadunacceptable cloudiness.

Example 11

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 11 41 29 42 43 17 23 44 45 PVOH 8 cps 88% DH 100100 100 100 100 100 100 100 100 CMC 2 Compatibilizing 18.13 18.13 18.1318.13 18.13 18.13 18.13 18.13 18.13 agent Variable Sugar alcohol 20.0020.00 20.00 20.00 20.00 20.00 20.00 20.00 20.00 (See the plasticizersolid table below) at RT Glycerol, Liquid 36.98 36.98 36.98 36.98 36.9836.98 36.98 36.98 36.98 Propylene Plasticizer Glycol Process AidSurfactant 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42

2.0 mil thick water-soluble films were cast according to formulae 11,41, 29, 42, 43, 17, 23, 44, and 45, conditioned for 24 hours, and thetransparency behavior of the water-soluble films was monitored. Thetransparency of the films was monitored for 30 days with exception oferythritol (formula 44), 26 days, and mannitol (formula 23), 21 days.The results are reproduced in the table below.

Sugar Alcohol Opacity at Heat of Formulae Sugar Alcohol Loading (phr) 30days Fusion (J/g) 11 Sorbitol 20 35.8 192 41 Isomalt 20 36.3 142 29Xylitol 20 36.8 247 42 Dulcitol 20 37.4 340 43 Pentaerythritol 20 38.6289 17 Maltitol 20 39.1 164 23 Mannitol 20 40.4 301 44 Erythritol 2041.2 329 45 Adonitol 20 41.6 232

Films according to formulae 42, 43, 17, 23, 44, and 45 having thedescribed amounts of dulcitol, pentaerythritol, maltitol, mannitol,erythritol, or adonitol as the sugar alcohol plasticizer that is a soliddemonstrated an undesirable cloudy appearance. In contrast, filmsaccording to formulae 11, 41, and 29 comprising xylitol, isomalt orsorbitol as the sugar alcohol plasticizer that is a solid at roomtemperature demonstrated an acceptable level of transparency. Theundesirable films had opacity values of 37.4% or greater while thedesirable films had opacity levels of 36.8% or less. Example 11 showsthat in films comprising 20 phr of the sugar alcohol plasticizer that isa solid at room temperature, films wherein the sugar alcohol plasticizerhad a heat of fusion of about 247 J/g or less were acceptablytransparent, with the exceptions of the films comprising sugar alcoholplasticizers that are a solid at room temperature with heats of fusionbelow 247 J/g but do not have two adjacent, sterically unhindered,hydroxyl groups in the same plane, maltitol and adonitol, the filmsbeing unacceptably cloudy. In contrast, films wherein the sugar alcoholplasticizer had a heat of fusion of about 289 J/g or greater at theseloading rates were unacceptably cloudy in appearance.

Example 12

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 13 46 47 48 19 31 49 50 25 PVOH 8 cps 88% DH 100100 100 100 100 100 100 100 100 CMC 2 Compatibilizing 18.13 18.13 18.1318.13 18.13 18.13 18.13 18.13 18.13 agent Variable Sugar alcohol 30.0030.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 (See the plasticizertable below) solid at RT Glycerol, Liquid 36.98 36.98 36.98 36.98 36.9836.98 36.98 36.98 36.98 Propylene Plasticizer Glycol Process AidSurfactant 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42 1.42

2.0 mil thick water-soluble films were cast according to formulae 13,46, 47, 48, 19, 31, 49, 50, and 25, conditioned for 24 hours, and thetransparency behavior of the water-soluble films was monitored. Thetransparency of the films was monitored for 30 days with exception oferythritol (formula 49), 26 days, and mannitol (formula 25), 21 days.The results are reproduced in the table below.

Sugar Alcohol Opacity at Heat of Formulae Sugar Alcohol Loading (PHR) 30days Fusion (J/g) 13 Sorbitol 30 35.7 192 46 Isomalt 30 37.0 142 47Dulcitol 30 37.3 340 48 Pentaerythritol 30 39.9 289 19 Maltitol 30 40.4164 31 Xylitol 30 40.8 247 49 Erythritol 30 40.8 329 50 Adonitol 30 42.4232 25 Mannitol 30 43.2 301

Films according to formulae 47, 48, 19, 31, 49, 50, and 25 having thedescribed amounts of dulcitol, pentaerythritol, maltitol, xylitol,erythritol, adonitol or mannitol as the sugar alcohol plasticizer thatis a solid demonstrated an undesirable cloudy appearance. In contrast,films according to formulae 13 and 46 comprising isomalt or sorbitol asthe sugar alcohol plasticizer that is a solid at room temperaturedemonstrated an acceptable level of transparency. The undesirable filmshad opacity values of 37.3% or greater while the desirable films hadopacity levels of 37.0% or less. Example 12 shows that in filmscomprising 30 phr of the sugar alcohol plasticizer that is a solid atroom temperature, films wherein the sugar alcohol plasticizer had a heatof fusion of about 192 J/g or less were acceptably transparent, with theexception of the film comprising a sugar alcohol plasticizer that are asolid at room temperature with a heat of fusion below 192 J/g but doesnot have two adjacent, sterically unhindered, hydroxyl groups in thesame plane, maltitol, the film being unacceptably cloudy. In contrast,films wherein the sugar alcohol plasticizer had a heat of fusion ofabout 232 J/g or greater at these loading rates were unacceptably cloudyin appearance.

Example 13

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 51 PVOH 23 cps, nominal 88% DH 100 CMC 3Compatibilizing agent 17.04 Xylitol Sugar alcohol plasticizer 8.52 solidat RT Sorbitol Sugar alcohol plasticizer 4.57 solid at RT Glycerol,Liquid plasticizer 36.98 Propylene Glycol Process Aid Surfactant 1.43Process Aid Antiblock 2.6 CMC 3 Carboxymethyl cellulose characterized bya viscosity of 2% solution at 25° C. of 20-80 cP and a degree ofsubstitution of 0.65-0.90

2.0 mil thick water-soluble films were cast according to formula 51,conditioned for 24 hours, and were tested for tear strength, solubility,tensile strength, elongation at break, and energy to break, as describedabove. The results are reproduced in the table below.

Property 51 Tear Strength MD (g/mil) 1159 Dissolution at 10° C. (s) 27.7Dissolution at 23° C. (s) 31.4 Tensile Strength (N/mm²) 32.8 Elongationat break (%) 519.1 Energy to break (J/mm²) 2.3

Example 13 shows that when additional processing aids for antiblockingwere added that good tear, tensile and solubility properties andacceptable transparency as visually observed were achieved.

Example 14

A water-soluble film was prepared with the ingredients identified belowin the amounts shown (phr).

Component Description 52 PVOH 23 cps, nominal 88% DH 100 CMC 2Compatibilizing agent 17.04 Xylitol Sugar alcohol plasticizer 8.52 solidat RT Sorbitol Sugar alcohol plasticizer 6.53 solid at RT Glycerol,Liquid plasticizer 36.98 Propylene Glycol Process Aid Surfactant 1.43

1.5 mil thick water-soluble films were cast according to formula 52,conditioned for 24 hours, and were tested for film peak load followed byseal peak load at different temperatures. The peak load ratio wasdetermined. The results are reproduced in the table below.

Film Peak Seal Peak Peak Heat Seal Load (N) Load (N) Load Ratio 275° F.(135° C.) 19.92 6.19 0.31 280° F. (138° C.) 19.92 6.72 0.34 285° F.(140.5° C.) 19.92 7.16 0.36 290° F. (143° C.) 19.92 6.21 0.31 295° F.(146° C.) 19.92 7.12 0.36 300° F. (149° C.) 19.92 8.37 0.42

Example 14 shows that acceptable peak load ratios are obtained for filmsthat are heat sealed at a temperature in the range of 275° F. to 300° F.(135° C. to 149° C.).

What is claimed:
 1. A water soluble film, consisting of a water solublemixture of a water soluble resin comprising polyvinyl alcohol, amodified polyvinyl alcohol, or a combination thereof, wherein thepolyvinyl alcohol or modified polyvinyl alcohol is present in an amountin a range of about 35 to about 90 wt. %, based on the total weight ofthe film, a compatibilizing agent selected from carboxymethyl cellulose(CMC), hydroxypropylated starch, and a combination thereof, a sugaralcohol plasticizer that is a solid at room temperature selected fromthe group consisting of isomalt, maltitol, sorbitol, xylitol, adonitol,and a combination thereof, and, optionally one or more excipientsselected from the group consisting of a plasticizer that is a liquid atroom temperature, a surfactant, an antiblocking agent, and an internalrelease agent, wherein the water soluble film is substantiallytransparent according to having an opacity of 37% or less for a 2.0 mmfilm, after storing for 30 days after film formation, wherein the sugaralcohol plasticizer that is a solid at room temperature has a heat offusion of 247 J/g or less and a concentration of 5 to 35 phr, and whenthe heat of fusion of a sugar alcohol plasticizer that is a solid atroom temperature is greater than 192J/g then its concentration is 20 phror less; and wherein the water soluble polyvinyl alcohol or modifiedpolyvinyl alcohol component of the film is characterized by a weightaverage molecular weight in a range of about 55,000 to about 80,000g/mol.
 2. The water soluble film of claim 1, wherein the sugar alcoholplasticizer that is a solid at room temperature is included in an amountof about 20phr or less.
 3. The water soluble film of claim 1, whereinthe sugar alcohol plasticizer that is a solid at room temperature isincluded in an amount of about 25 to about 35 phr and is characterizedby a heat of fusion of about 192 J/g or less.
 4. The water soluble filmof claim 1, wherein the compatibilizing agent is carboxymethylcellulose; wherein the sugar alcohol plasticizer that is a solid at roomtemperature comprises xylitol and a second sugar alcohol plasticizerthat is a solid at room temperature; and wherein the water soluble film,when 2.0 mils thick, dissolves in less than 50 seconds in water at 23°C.
 5. The water soluble film of claim 1, wherein the water soluble filmhas a tear strength of at least 400 g/mL.
 6. The water soluble film ofclaim 4, wherein the ratio of compatibilizing agent to xylitol is about3:1.
 7. The water soluble film of claim 1, wherein the water solublefilm is edible.
 8. The water-soluble film of claim 1, wherein the watersoluble resin comprises polyvinyl alcohol.
 9. The water soluble film ofclaim 8, wherein the water soluble resin comprises polyvinyl alcoholwith a degree of hydrolysis in a range of about 75% to about 99%. 10.The water soluble film of claim 1, wherein the sugar alcohol plasticizerthat is a solid at room temperature is included in the film an amount ina range of about 10 to about 25 parts per hundred parts resin (phr). 11.The water soluble film of claim 10, wherein the sugar alcoholplasticizer that is a solid at room temperature comprises at least twosugar alcohol plasticizers that are solid at room temperature.
 12. Thewater soluble film of claim 1, wherein the sugar alcohol plasticizerthat is a solid at room temperature is characterized by a heat of fusionof less than about 192 J/g.
 13. The water soluble film of claim 1,wherein the sugar alcohol plasticizer that is a solid at roomtemperature comprises a mixture of xylitol with at least one member ofthe group consisting of maltitol, sorbitol, and isomalt.
 14. The watersoluble film according to claim 1, wherein the compatibilizing agent iscarboxymethyl cellulose.
 15. The water soluble film according to claim14, wherein the carboxymethyl cellulose has a degree of substitution ina range of about 0.6 to about 0.95.
 16. The water soluble film of claim1, wherein the compatibilizing agent is included in the film in anamount in a range of about 10 to about 25 phr.
 17. The water solublefilm of claim 1, wherein the ratio of compatibilizing agent to sugaralcohol plasticizer that is a solid at room temperature is about 2:1 toabout 1:2.
 18. The water soluble film of claim 1, comprising aplasticizer that is a liquid at room temperature selected from the groupconsisting of glycerol, diglycerol, propylene glycol, ethylene glycol,diethyleneglycol, triethylene glycol, tetraethyleneglycol, polyethyleneglycols up to MW 400, 2 methyl 1,3 propane diol and combinations of theforgoing.
 19. The water soluble film according to claim 18, wherein theplasticizer that is a liquid at room temperature is present in the filman amount in a range of about 25 to about 50 phr.
 20. The water solublefilm of claim 1, comprising a surfactant.
 21. The water soluble filmaccording to claim 20, wherein the surfactant is selected from the groupconsisting of dioctyl sodium sulfosuccinate, lactylated fatty acidesters of glycerol and propylene glycol, lactylic esters of fatty acids,sodium alkyl sulfates, polysorbate 20, polysorbate 60, polysorbate 65,polysorbate 80, lecithin, acetylated fatty acid esters of glycerol andpropylene glycol, and acetylated esters of fatty acids, and combinationsof any of the forgoing.
 22. The water soluble film according to claim21, wherein the surfactant is present in the film in an amount of lessthan about 2 phr.
 23. The water soluble film of claim 1, wherein thefilm is heat sealable.
 24. The water soluble film of claim 22, whereinthe film is thermoformable.
 25. The water soluble film of claim 1,wherein the film maintains a Δ% opacity of 2.0% or less for at least 4days longer than an otherwise identical film having no compatibilizingagent.
 26. An article, comprising a water soluble packet comprising afilm of claim
 1. 27. The article of claim 26, wherein the packetcontains a food item.
 28. The water soluble film of claim 1, comprisinga water soluble mixture of polyvinyl alcohol, carboxymethylcellulose,xylitol, sorbitol, and glycerol; wherein the ratio ofcarboxymethylcellulose to xylitol is about 3:1.
 29. The water-solublefilm of claim 1, comprising one or more excipients selected from thegroup consisting of a plasticizer that is a liquid at room temperature,a surfactant, and an antiblocking agent.